Project description:In this study we used a high-throughput method for assaying methylation of CpG sites simultaneously in a single sample for identifying differences in methylation observed in tissues ranging from normal liver to pre-neoplastic (cirrhosis) and neoplastic (HCC) states. Since there are important clinical and prognostic differences among HCC patients due to etiology, this study was designed to focus on HCC due to HCV-infection, a more common etiology of HCC among Western countries cross-sectional: 20 cirrhosis, 20 HCC, and 16 normal patients, 87 arrays
Project description:In this study we used a high-throughput method for assaying methylation of CpG sites simultaneously in a single sample for identifying differences in methylation observed in tissues ranging from normal liver to pre-neoplastic (cirrhosis) and neoplastic (HCC) states. Since there are important clinical and prognostic differences among HCC patients due to etiology, this study was designed to focus on HCC due to HCV-infection, a more common etiology of HCC among Western countries
Project description:Epigenetic deregulation is a critical event in human malignancies. A number of DNA methylation markers are currently under evaluation as diagnostic and prognostic biomarkers for many cancers. However, its potential role in hepatocellular carcinoma (HCC) is under-explored. Aims: To develop a DNA methylation-based prognostic signature in surgically resected HCC Tumors from 224 HCC resected patients, 10 normal Liver individuals and 9 Cirrhotic patients were analyzed. Methylome profiling was done with Illumina HumanMethylation450 (485,000 CpG, 96% of known CpG islands). We selected probes in CpG islands located in promoters, hypermethylated (B value higher than 50%) in at least 5% of the tumors and hypomethylated (B value lower than 33%) in more than 90% of normal liver.
Project description:Chronic infections by hepatitis B virus (HBV) and hepatitis C virus (HCV) appear to be the most significant causes of hepatocellular carcinoma (HCC). Aberrant promoter methylation is known to be deeply involved in cancer, including HCC. In this study, we analyzed aberrant promoter methylation on genome-wide scale in 6 HCCs including 3 HBV-related and 3 HCV-related HCCs, 6 matched noncancerous liver tissues and 3 normal liver tissues by methylated DNA immunoprecipitation-on-chip analysis. Candidate genes with promoter methylation were detected more frequently in HCV-related HCC. Candidate genes methylated preferentially to HBV-related or HCV-related HCCs were detected and selected, and methylation levels of the selected genes were validated using 125 liver tissue samples, including 61 HCCs (28 HBV-related HCCs and 33 HCV-related HCCs) and matched 59 matched noncancerous livers, and 5 normal livers, by quantitative methylation analysis using MALDI-TOF mass spectrometry. Among analyzed genes, preferential methylation in HBV-related HCC was validated in 1 gene only. However, 15 genes were found methylated preferentially in HCV-related HCC, which was independent from age. Hierarchical clustering of HCC using these 15 genes stratified HCV-related HCC as a cluster of frequently methylated samples. The 15 genes included genes inhibitory to cancer-related signaling such as RAS/RAF/ERK and Wnt/b-catenin pathways. It was indicated that genes methylated preferentially in HCV-related HCC exist, and it was suggested that DNA methylation might play an important role in HCV-related HCC by silencing cancer-related pathway inhibitors. we analyzed aberrant promoter methylation in 6 HCC clinical samples (including 3 HBV-related HCCs and 3 HCV-related HCCs) and their matched noncancerous tissues on genome-wide scale by the method. Candidate regions of promoter methylation preferentially to HBV-related HCC and HCV-related HCC were selected, and the methylation levels of these genes were measured quantitatively using MALDI-TOF mass spectrometry. Expression levels of these 6 pairs of HCC and 4 more pairs of HCCs and surrounding noncancerous tissues were analyzed by expression array and are reported in this Series. <br><br>This experiment was reloaded in November 2010 after additional curation. this dataset is part of the TransQST collection.
Project description:Chronic infections by hepatitis B virus (HBV) and hepatitis C virus (HCV) appear to be the most significant causes of hepatocellular carcinoma (HCC). Aberrant promoter methylation is known to be deeply involved in cancer, including HCC. In this study, we analyzed aberrant promoter methylation on genome-wide scale in 6 HCCs including 3 HBV-related and 3 HCV-related HCCs, 6 matched noncancerous liver tissues and 3 normal liver tissues by methylated DNA immunoprecipitation-on-chip analysis. Candidate genes with promoter methylation were detected more frequently in HCV-related HCC. Candidate genes methylated preferentially to HBV-related or HCV-related HCCs were detected and selected, and methylation levels of the selected genes were validated using 125 liver tissue samples, including 61 HCCs (28 HBV-related HCCs and 33 HCV-related HCCs) and matched 59 matched noncancerous livers, and 5 normal livers, by quantitative methylation analysis using MALDI-TOF mass spectrometry. Among analyzed genes, preferential methylation in HBV-related HCC was validated in 1 gene only. However, 15 genes were found methylated preferentially in HCV-related HCC, which was independent from age. Hierarchical clustering of HCC using these 15 genes stratified HCV-related HCC as a cluster of frequently methylated samples. The 15 genes included genes inhibitory to cancer-related signaling such as RAS/RAF/ERK and Wnt/b-catenin pathways. It was indicated that genes methylated preferentially in HCV-related HCC exist, and it was suggested that DNA methylation might play an important role in HCV-related HCC by silencing cancer-related pathway inhibitors.
Project description:Hepatocellular carcinoma (HCC) is the second most common cause of cancer deaths worldwide. Altered DNA methylation landscapes are ubiquitous features of cancer. Interpretation of epigenetic aberrations in HCC is confounded by effects of multiple etiologic drivers and underlying cirrhosis in most cases. We globally profiled the DNA methylome of 34 normal livers and 122 primary liver disease tissues arising in the setting of chronic hepatitis B (HBV) or C (HCV) viral infection, alcoholism (EtOH), and other causes to examine how these environmental agents impact DNA methylation in a manner that contributes to liver disease. Our results demonstrate that each etiologic factor leaves unique and overlapping signatures on the DNA methylome. CpGs aberrantly methylated in cirrhosis-HCV and conserved in HCC were enriched for cancer driver genes, suggesting a pathogenic role for HCV-induced methylation changes. Additionally, large genomic regions displaying stepwise hypermethylation or hypomethylation during disease progression were identified. HCC-HCV/EtOH methylomes overlap highly with cryptogenic HCC, suggesting shared epigenetically deregulated pathways for hepatic carcinogenesis. Finally, overlapping methylation abnormalities between primary and cultured tumors unveil highly conserved epigenetic signatures in HCC. Taken together, this study characterizes progressive liver DNA methylome changes under exposure to detrimental environmental agents and illuminates possible biomarkers for early detection of HCC. 156 primary tissues and 25 cultured normal and HCC cell lines
Project description:In this study, we used the Affymetrix HG-U133A 2.0 GeneChip for deriving a multigenic classifier capable of predicting HCV+cirrhosis with vs without concomitant HCC. We studied gene expression in cirrhotic tissues with (N=16) and without (N=47) HCC. Keywords: cross-sectional Liver tissue samples were obtained from patients waiting for liver transplantation. For each sample, RNA was extracted and hybridized to an Affymetrix GeneChip. This dataset is part of the TransQST collection.
Project description:We applied small RNA Solexa sequencing technology to identify microRNA expression in human liver samples from surgically removed liver tissues including three normal liver tissues (distal normal liver tissue of liver hemangioma), an hepatitis B virus (HBV)-infected liver, a severe chronic hepatitis B liver, two HBV-related hepatocellular carcinoma (HCC), an hepatitis C virus (HCV)-related HCC, and an HCC without HBV or HCV infection. All samples were collected with the informed consent of the patients and the experiments were approved by the ethics committee of Second Military Medical University, Shanghai, China. We investigated the miRNome in human normal liver and suggested some deregulated abundantly expressed microRNAs in HCC. center_name: National Key Laboratory of Medical Immunology & Institute of Immunology, Second Military Medical University, Shanghai, China. Examination of miRNome in human liver samples from surgically removed liver tissues including three normal liver tissues (distal normal liver tissue of liver hemangioma), an hepatitis B virus (HBV)-infected liver tissue, a severe chronic hepatitis B liver tissue, an HBV-related hepatocellular carcinoma (HCC) tissue and adjacent liver tissues of different regions,an HBV-related HCC tissue and adjacent liver tissue, an hepatitis C virus (HCV)-related HCC tissue and adjacent liver tissue, and an HCC without HBV or HCV infection and adjacent liver tissue. All 15 human liver tissue samples.
Project description:Introduction: Hepatocellular carcinoma (HCC) is one of the most aggressive solid tumors and oncogenic pathways (e.g Akt, IGF signaling) are often activated in high proliferating HCC. Among several genetic alterations, epigenetic changes seem to be involved in the development and progression of HCC. DNA hypermethylation of promoter regions is almost always associated with transcriptional silencing and can lead to inactivation of tumor suppressor genes (TSG) in cancer cells. Aim: (1) To identify genes differently methylated in a subclass of HCC associated with proliferation and, (2) To correlate methylation changes with activation of molecular pathways. Methods: gDNA of 20 HCC, 8 cirrhotic and 8 normal liver samples was extracted and the methylation status was detected by the Illumina HumanMethylation27 BeadChip and immunohistochemistry of p-AKT, pIGF IR, p-S6 was analyzed. Results: Unsupervised clustering clearly classified normal livers, cirrhosis and HCC in 3 different groups. 961 genes were significantly hypermethylated in HCC compared to cirrhotic and 3942 genes showed hypermethylation in cirrhotic compared to normal liver tissue. 163 genes showed stepwise significant hypermethylation from normal to cirrhotic to HCC, including well described (p16, SOCS2, SFRP5, RBP1) and potential (SRD5A2, PCDH8, IGF-1R, UCHL1) TSGs, and the miR-10a. 133 genes were specifically hypermethylated in HCC. Among them the transcription factors GATA2, DLX1, and KLF14, all significantly inversely correlated to gene expression (p=0.003, p=0.03, and p=0.007, respectively). The methylation status of SOCS2 (p=0.025) and DLX1 (p=0.025) was significantly correlated to phosphorylation of IGFR1. Samples with RBP1 hypermethylation showed significantly higher AFP serum levels (p=0.018). Conclusion: Whole genome methylation analysis markedly classifies normal, cirrhotic and HCC samples. 8 TSGs play a key role in this stepwise progression of hypermethylation in the development of HCC and could be a promising point of action in anticancer therapy. Genomic DNA extracted from fresh frozen tissue specimens and cell lines was hybridized to genome-wide mthylation beadarray after bisulphite treatment. Keywords: DNA methylation, hepatocellular carcinoma, tissue, cell line
Project description:A large fraction of HCC in Peru arises in younger, non-cirrhotic patients. Global DNA methylation analysis of the HCC and non-tumor liver (NTL) tissues demostrate a profound overhaul of the developmental DNA methylation programme culminating in an global hyper-methylated pattern in HCC. We used microarrays to compare global DNA methylation between tumor and non-tumor liver tissues and identified CpGs and ontologies that are distinctively differentially methylated between subsets.